The formation of formic acid by hydrothermal oxidation of glucose, a model compound of carbohydrate biomass, was investigated for applying formic acid as a source of hydrogen production. All experiments were conducted in a batch reactor made of SUS 316 tubing, providing an internal volume of 5.7cm 3. A 30 wt% hydrogen peroxide solution was used as an oxidant. The hydrothermal oxidation of glucose with and without the addition of alkali was carried out with temperature varying from 250 to 300°C, reaction time varying from 30 s to 90 s, and H2O2 supply varying from 80% to 140%. Results showed that at a mild temperature of 250°C, glucose was converted into formic acid in an excellent yield of 75% when adding alkali. This result should facilitate the study on the production of hydrogen from carbohydrate biomass via formic acid.